Automatic adjuster for push rods



June 7,1927.

J. E. TlTUS AUTOMATIC ADJUSTER FOR PUSH RODS Flled Feb. 5, 1924 lliIIllrlllll. llll-l'lll' 'llll IIIIIIII Patented June 7, 1 9 27.

f 1 UNITED STATES I 1,631,563 PATENT OFFICE.

Joan 1:. runs, or cnrca'eo, rumors.

urom'rrc amuse-En roa rusn aons.

' Application ma, Febrnary 5, 19a. Serial No. 690,878.

This invention relates ,more particularly to automatic means for adjusting the lengt of the push rods which are part of the valve lifting mechanism of poppet valve engines.

The objects are as follows: to provide means for automaticallyaccomplishing the initial adjustment of the length of the push rod and a continuous automatic adjustment for the shortening of they parts during the operation of the valves due to wear and other causes. To provide means for c0mpensating for the temperaturechanges in the length of the parts which form the op erating connection between the operating means and-the valve, .Toprovide a device for the above purposes which may be easily installed on certain standard makes of pop- .in the following description.

pet valve engines now in extensive use. Other objects and advantages Wlll appear The accompanying drawing shows a sectional view ofan engine show ng the poppet valve and lifter mechanism.

My device may be easily installed in the engine shown without any change. being made in. the reglpllar engine parts relating to the device. ese parts are briefly described as follows: The poppet valve 1 seats at 2 in the engine frame 3. The stem of the valve 1 is ided through the boss 4 in the frame3 and the lower end 5 of the valve stem carries a springcup 6 resting on the pin 7 in the end 5.

The push rod 8is guided in vertical alignment with the valve stem 5 through the boss '9 in-the lower part of the engine frame 3.

The lower end of the push rod 8 rests on the cam 10 which is an integral part of the time shaft 11. The valvespring 12 exerts pressure between the spring cup 6 and a seat in the engine frame 3..

The valve stem and the push rod are fitted in place so that there is as small an amount of clearance as possible at 13 when the push rod is in itsdown position. The general theory is that there must be a slight .amount of clearance in the lifter mechanism when the en ine iscold so that, when the parts ex an under the temperatures developed y the operation of the engine, the valve will not be held off its seat inthe down position of thepush ro'd. These valve lifter parts wear. ra idly so asv to cause an excessive amount 0 clearance at 13 which throws the valves out of time, reduces their clearance or lift, and makes objectionable noise. My device remedies the above defects and also compensates for possible temperature changesin the length of valve stem and push rod, as will be pointed out below.

I provide the clutch cone 15, the cup 16,

utch

the clutch spring 17, the plurality of.

balls 19, and the ball retainer 20.

The cone 15 has a stepped bore which enables the cone to be seated on the upper end of the push rod and also receive the lower end of the valve stem .5, without making any changesin theold parts, the valve stem being smaller in diameter than the push rod. The cup 16 is slipped on the end of the valve stem and the spring17 inserted between the bottom of the cup 16 and the top of the cone 15 holding the cup up against 1 the pin 7 and pressing the cone and push rod downward. The skirt or'walls of the cup 16 overhang the conical edge of the I member 15 forming a tapering annular chamber 18 in which the clutch balls 19 operate. The balls 19 are loosely contained in pockets in the retainer ring 20 permitting the balls to independently find the point at which they will wedge in the tapering space 18.-

The adjuster parts are easily. placed in position by lifting up on the end of the valve stem 5. As the valve stem is lowered the ballretainer=20is pressed up into the cup 16 to-prevent. the balls 19 from wedging before the valve 1 has seated. When the stem is lowered, the ball retainer is released and the balls 19' drop by gravity into the- 'wedg parts connected to it. The on 16 is held up.

against the pin 7 in the va ve stem 5, by

the clutchspring 17 which at the same time operates topress the cone 15 and the push rod 8 for further downward movement.

The relative movement of clutch and cone to cause the balls to lock, is slight. the length of the connecting parts between the valve 1 and the cam'10 is. automatically adjusted when the parts are cold, the valve would be held off its seat when the parts are expanded under heat, except for provisions Since i which I make as a part of my invention to adapt the invention for such special cases.

I provide the cup 16 of such proportionatestrength that its walls will yield under a small part of the pressure from the valve In more general terms, a clutch C is inserted in the connecting member'B between the operating member 0 and the operated member V. The operated member is spring pressed or otherwise yicldingly held against. a seat or stop S, and is intermittently lifted and lowered by the operating'member O. The space hetweenflthe members V and O is substantially constant as to length during geriod and is occupied bythe inoperative the connection The connection B is caused to fill or expand to fill the space by the spring 17 or other methods and the clutch C operates to allow relative change of the length of the connection B to allow B to fill the space between V and B, but operates to resiliently resist any return change in the adjustment of the connection To'compensate for changes in the length of the parts themselves during operation of the mechanism, the connecting member is proportioned in elasticity to yield the necessar amount when still under t-heforce that yie dingly holds the operated member towards its seat, so that the operated mem: her is allowed to seat after the operating member 0 has stopped, within certain limits. v

In the automobile gas engine the valve lifting parts are made so that there is a gap in the lifting parts, as at 13, to'compensate for the temperature changes in the lengths of the valve stem and other parts. When the parts are the shortest. the cam 10 first moves the push rod 8 up into contact with the end of the valve stem 5 and then the valve is lifted.

With my device in place, the action is precisely the same, in the actual vmovement of the parts. The upwardmovement of the push rod 8 exerts pressure at once through the clutch C against the pressureof the spring 12.- Of course the full pressure of the valve spring 12 mustbe overcome before the valve can be lifted off the seat; and

the inside diameter of the shell 16 and the angle of the cone 15 is proportioned so that the shell will yield under but a small part of the weight of the spring 12. This allows the push rod to move up the required amount before it can lift thevalve.

For example, when the initial tension of the valve spring is about thirty pounds, the proportions are made so that the shell walls spring out one one thousandth to one and one quarter thousandths of an inch. The edge angle of the cone is eight degrees and the cone will move up eight thousandths of an inch under about ten pounds pressure. After a load of ten pounds, the resistance of the shell walls increases and there is proportionately less relative movement between the cone andthe shell for increasing loads over quite a large range of ressure. Therefore the clearance providbd is practically independent of the weight of the valve spring.

The resiliency of the device also allowsslippage at certain parts of the valve movement, and the valve works down again after it has been held up from seating and the clutch has set'to prevent the valve returning all of the way down.

While I have shown but one embodiment of my invention and in but one type of structure, the form of my device may be changed and the invention as a whole applied to similar structures of mechanism which operate under similar conditions as outlined in the preceding paragra h, withput departing from the spirit of t e inven- My claims are:

1. In combination with a poppet valve stem and a push rod in axial alignment and approximately abutting end to end, the push r0 being slightly larger in diameter than the valve stem, a cone member seating on the extending edge of the push rod and receivbetween the cone and on 2. In combination'witli an operated member yieldingly held by a given force acting to direct the operated member against a seat; an operating member acting to mtermit-tently raise the first'mentioned member from its seat, acting against the given force, and to allow the first mentioned member to return to its seat, the two mentioned members being in substantially fixed spaced relation during the inoperative period; and a connecting member having a clutch incorporated in 1ts structure which is adapted to allow the connecting member to change in length to fill the space between the operating and the o erated members during the inoperative period but which resists a return change in the operating member for intermittently raisinglength of the connecting member, the clutch force.

3. In combination with an operated member yieldingly held against a seat and an the first member from its seat and allowing it to return, the two members in substantially fixed spaced relation during the inoperative period, a connecting member divided into parts which are spring pressed apart between the two said members. a clutch between said parts adapted to allow' separation and to resist contraction, said clutch being structurally adapted to spring and yield a slight amount when under ,the load of lifting the first member.

4. In an automatic valve adjuster, a clutch cone, a clutch shell having a resilient rim portion surrounding the edge of the cone, :1

series of balls disposed in the wedging space between the edge of the cone and the inside of the rim of the shell, andmeans for causing relative movement between the shell and the cone in one direction.

- 5. In combination in a poppet valve lifting mechanism having two thrust members spaced apart at adjoining ends, a clutch cone slidable onone member and adapted to be engaged by the second member, a clutch shell mounted on the first mentioned thrust memher, and a series of balls coacting with the shell and the cone to form an automatic clutch.

6. In an automatic valve adjuster in combination with two valve lifting thrust members in spaced relation at adjoining ends, a

cone seated on the end of one of the thrust members and slidable on the-second member, a stop on the second mentioned'member, a cup shaped shell mounted on the second member, adapted to move up against the said stop, and having a resilient rim surrounding the cone, a series of balls adapted-to wedge between the cone and the shell, and a spring acting between the cone and the shell to move the shell up, against the stop and to press the cone down on the end of the member on which it is seated.

JOHN E. TITUS. 

